Solar power backup system

Battery Technology is more affordable than ever.

Battery technology has come a long way in just a few short years. While battery storage is still expensive (definitely more expensive than just using grid-tied solar) there are cases where a battery backup or off-grid solar system is a great solution for a home or property. For some, having the security of battery storage during a storm or grid outage provides important piece of mind. For others, spending tens-of-thousands of dollars to pay for utility access simply does not make sense if a less expensive (and greener!) alternative is available.

With solar battery storage, there are two main ways to go about it. A grid-tied battery backup system, and an independent off-grid battery system.

Solar powered battery back-up
A battery backup system serves as a power backup for your home in the event of a power outage. When paired with a solar system, a battery backup system charges up with some of your excess solar production and stands ready to activate if it is needed. Battery- backup storage options like this are what solutions like the Tesla Powerwall and Sonnenbatterie products achieve.
A fully independent off-grid solar battery system.
For some people, being entirely off-grid and disconnected from the utility is the best, and most cost-effective solution. Whether it is a hunting camp in the mountains or just a large plot of land that does not currently have utility power run to it, an off-grid solar system can provide power for less that it would cost to pay the utility to connect to the property. An off-grid solar system is comprised of a larger battery bank that supplies electricity whenever the solar panels are not providing enough power to run your appliances.

Great, but how much storage do I need?

Deciding that a solar battery storage system might be a great addition to your home or property is one thing, determining exactly how much you might need is quite another. When sizing both off-grid and grid-tied systems, there is one thing more important that anything else: your electricity usage. Do you have an ultra efficient refrigerator and only use LED light bulbs? Do you have a well and need power to run your pump and get water to your sink and shower? Is your water heater electric? What kind of heating system do you have? All of these items factor into how much electricity you need to store, and how much you may need.

Off-grid systems need more battery storage than grid tied systems. After all, those batteries are the only source of electricity that you have when the sun goes down! A grid-tied system is a bit simpler. Generally, you only need to store electricity to get you through the night, or to offset the few h
ours that you might lose power. Most grid-tied battery systems are used to power the critical loads in the home. Critical loads are things like well pumps, refrigerators, and the controls/thermostats on a oil or gas heating system. If the power goes out, the battery backup is there to ensure that you have water, your heat stays on, and your food doesn’t spoil.

Costs

The costs of a battery system can vary greatly. A small grid-tied battery backup system could cost as little as $4, 000; a fully off-grid 3, 000 sq. foot home could require an $80, 000 solar battery system to maintain functionality year-round. Ultimately it comes down to what your goals are for the home or property, and the value you place on being fully energy independent, or replacing that dirty generator with a clean battery backup for emergencies.